[unreadable] The overall objective of this proposal is to develop, implement, and evaluate tissue-tagging magnetic resonance imaging methods for localized measurements of pulmonary motion and deformation. This will allow, for the first time, noninvasive assessments of regional pulmonary mechanical function. We have recently developed a method using tissue-tagging magnetic resonance imaging (MRI) to assess local pulmonary mechanics. In this method, we apply a spin-labeled grid to the lung tissue, and then track the locally and temporally resolved expansion pattern of the underlying tissue during respiration by imaging the deformed grid with MRI. By evaluating the alteration of the grid pattern associated with lung deformation the mechanical properties exhibited by all regions of the lung may be obtained. We hypothesize that there is, a direct correlation between the compliance measurements determined by MRI and the measurements from pulmonary function tests. However, in order to fully achieve this utility, methodological and technical obstacles must be overcome. Thus, the goal of the proposed research is to optimize the MRI approach for quantifying patterns of lung motion during respiration, and to use this approach to develop novel mechanical concepts accounting for regional variations of function. This goal will be accomplished by pursuing the following specific aims: [unreadable] [unreadable] 1. To optimize MRI methods for measuring 3D lung deformation in a complete respiratory cycle. [unreadable] 2. To develop data analysis methods to quantify local parenchymal displacements associated with lung motion and deformation. [unreadable] 3. To evaluate these MRI methods for quantitative assessment of regional lung mechanical function. [unreadable] [unreadable] It is anticipated that such a method will lead to a better understanding of the mechanics of normal lung expansion, and permit the evaluation of pathological conditions in which regional mechanical function of the lungs is affected. [unreadable] [unreadable]